Filters are easy. A full tank isn't necessary but it is better than an empty one. Anyway you slice it priming will be necessary. Personally I prefer not not dump in fuel from the old filter. I pour in fuel additive or diesel purge but that's not necessary either. Remove both filters, install the new ones and pump the primer until you don't see any more bubbles in the clear fuel lines. If ultimately your car won't start you need to prime some more. It's a bit messy so expect to spill a little fuel in the process. Soup to nuts it shouldn't take more than 15-20 minutes. Less the next time you do it.

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LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold